U.S. patent application number 16/435547 was filed with the patent office on 2020-12-10 for differential thrust vectoring system.
This patent application is currently assigned to Bell Helicopter Textron Inc.. The applicant listed for this patent is Bell Helicopter Textron Inc.. Invention is credited to Kirk Landon Groninga, Daniel Bryan Robertson.
Application Number | 20200385110 16/435547 |
Document ID | / |
Family ID | 1000004485764 |
Filed Date | 2020-12-10 |
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United States Patent
Application |
20200385110 |
Kind Code |
A1 |
Groninga; Kirk Landon ; et
al. |
December 10, 2020 |
DIFFERENTIAL THRUST VECTORING SYSTEM
Abstract
A differential thrust vectoring system including a first
thruster rotation assembly configured to rotate a first thruster
relative of an aircraft, a second thruster rotation assembly
configured to rotate a second thruster of an aircraft, and an
actuator. The system is configured such that actuation of the
actuator causes disparate rotation about the tilt axis of the first
and second thrusters.
Inventors: |
Groninga; Kirk Landon;
(Keller, TX) ; Robertson; Daniel Bryan;
(Southlake, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bell Helicopter Textron Inc. |
Fort Worth |
TX |
US |
|
|
Assignee: |
Bell Helicopter Textron
Inc.
Fort Worth
TX
|
Family ID: |
1000004485764 |
Appl. No.: |
16/435547 |
Filed: |
June 9, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64C 27/52 20130101;
B64C 11/001 20130101; F16H 1/28 20130101; B64C 27/57 20130101; B64C
27/58 20130101; B64C 27/80 20130101; B64C 27/20 20130101; B64C
13/24 20130101; B64C 5/06 20130101; B64C 29/0033 20130101 |
International
Class: |
B64C 27/80 20060101
B64C027/80; B64C 29/00 20060101 B64C029/00; B64C 27/58 20060101
B64C027/58; B64C 5/06 20060101 B64C005/06; B64C 13/24 20060101
B64C013/24; B64C 27/52 20060101 B64C027/52; B64C 27/57 20060101
B64C027/57; B64C 11/00 20060101 B64C011/00; B64C 27/20 20060101
B64C027/20; F16H 1/28 20060101 F16H001/28 |
Claims
1. A differential thrust vectoring system, comprising: a first
spindle configured to be coupled for common rotation about a tilt
axis with a first thruster; a second spindle configured to be
coupled for common rotation about the tilt axis with a second
thruster; and an actuator configured to be coupled between the
first spindle and an airframe; wherein the differential thrust
vectoring system is configured such that actuation of the actuator
would cause disparate rotation about the tilt axis of the first
spindle and the second spindle.
2. The differential thrust vectoring system of claim 1, further
comprising: a planetary gear system coupled between the first
spindle and the second spindle.
3. The differential thrust vectoring system of claim 2, wherein the
planetary gear system comprises: a ring gear coupled for common
rotation with either the first spindle or the second spindle; a
non-rotatable sun gear; and a plurality of planetary gears coupled
for common rotation with whichever of the first spindle and the
second spindle that is not coupled for common rotation with the
ring gear.
4. The differential thrust vectoring system of claim 2, wherein the
planetary gear system comprises: a non-rotatable ring gear; a
plurality of planetary gears coupled for common rotation with
either the first spindle or the second spindle; and a sun gear
coupled for common rotation with whichever of the first spindle and
the second spindle that is not coupled for common rotation with the
plurality of planetary gears.
5. The differential thrust vectoring system of claim 2, wherein the
actuator is either a linear actuator or a rotary actuator.
6. The differential thrust vectoring system of claim 2, wherein the
actuator is configured to move from a first position wherein a
first thrust vector of the first thruster is substantially parallel
to a second thrust vector of the second thruster to a second
position wherein the first thrust vector is askew to the second
thrust vector.
7. A differential thrust vectoring system, comprising: a first
spindle configured to be coupled for common rotation about a tilt
axis with a first thruster; a second spindle configured to be
coupled for common rotation about the tilt axis with a second
thruster; a main actuator configured to be coupled between the
first spindle and an airframe; and a trim actuator coupled between
the first spindle and the second spindle; wherein the differential
thrust vectoring system is configured such that actuation of the
main actuator would cause common rotation about the tilt axis of
the first spindle and the second spindle and actuation of the trim
actuator would cause rotation about the tilt axis of the second
spindle relative to the first spindle.
8. The differential thrust vectoring system of claim 7, wherein the
main actuator is either a linear actuator or a rotary actuator and
the trim actuator is either a linear actuator or a rotary actuator,
and the main actuator is one of pneumatic, hydraulic, electric, and
electromagnetic, and the trim actuator is one of pneumatic,
hydraulic, electric, and electromagnetic.
9. The differential thrust vectoring system of claim 8, wherein the
first spindle and the second spindle are configured to transmit at
least one of mechanical, electrical, and hydraulic power
therethrough.
10. The differential thrust vectoring system of claim 9, wherein
the differential thrust vectoring system is configured such that
failure of the trim actuator and/or the main actuator will result
in thrust vectors of the first thruster and the second thruster
assuming a substantially parallel relationship.
11. The differential thrust vectoring system of claim 9, wherein
the differential thrust vectoring system is configured such that
failure of the trim actuator and/or the main actuator will result
in thrust vectors of the first thruster and the second thruster
assuming a predetermined skewed relationship.
12. An aircraft, comprising: a fuselage; an airframe; a first
thruster having a first thrust vector; a second thruster having a
second thrust vector; and a differential thrust vectoring system,
comprising: a first spindle coupled for common rotation about a
tilt axis with the first thruster; a second spindle coupled for
common rotation about the tilt axis with the second thruster; and
an actuator coupled between either the first spindle and the
airframe; wherein the differential thrust vectoring system is
configured such that actuation of the actuator would cause rotation
about the tilt axis of the first spindle and the second
spindle.
13. The aircraft of claim 12, further comprising: a main rotor; and
a planetary gear system coupled between the first spindle and the
second spindle, the planetary gear system being configured such
that when the actuator is in a forward-flight position the first
thrust vector and the second thrust vector are substantially
parallel and when the actuator is in a hover position the first
thrust vector and the second thrust vector are skewed, wherein an
angle between the first thrust vector and the second thrust vector
are configured to counter a torque effect of the main rotor.
14. The aircraft of claim 13, further comprising: a vertical
stabilizer configured to counter the torque effect of the main
rotor during forward flight.
15. The aircraft of claim 13, wherein the first thruster and the
second thruster comprise ducted fans.
16. The aircraft of claim 13, wherein the actuator is configured to
assume the hover position in failure.
17. The aircraft of claim 12, further comprising: a trim actuator
coupled between the first spindle and the second spindle, wherein
actuation of the trim actuator would cause rotation about the tilt
axis of the second spindle relative to the first spindle.
18. The aircraft of claim 17, wherein the actuator is either a
linear actuator or a rotary actuator and the trim actuator is
either a linear actuator or a rotary actuator, and the actuator is
one of pneumatic, hydraulic, electric, and electromagnetic, and the
trim actuator is one of pneumatic, hydraulic, electric, and
electromagnetic.
19. The aircraft of claim 18, wherein the first spindle and the
second spindle are configured to transmit at least one of
mechanical, electrical, and hydraulic power therethrough.
20. The aircraft of claim 19, wherein the differential thrust
vectoring system is configured such that failure of the trim
actuator and/or the actuator will result in the first thrust vector
and the second thrust vector assuming a substantially parallel
relationship or a predetermined skewed relationship.
Description
BACKGROUND
[0001] Similar to tiltrotor aircraft, compound helicopters aspire
to combine the vertical takeoff and landing, as well as hovering,
capabilities of a traditional helicopter with the range and speed
of an airplane. In order to accomplish this goal, compound
helicopters generally include a traditional helicopter rotor to
provide lift and directional thrust during low speed horizontal
movement and forward-facing thrusters and fixed wings to provide
forward thrust and vertical lift in high speed forward-flight.
Various types of forward-facing thrusters have been included on
compound helicopters, including jet engines and propellers. Various
means have also been implemented to counter the torque effect of
the main rotor, such as including a traditional tail rotor, having
different blade pitch on the opposing forward-facing propellers, or
by using coaxial contra-rotating rotors.
[0002] Placing a fan inside a duct can result in a system that
produces more thrust for the same power. This increase in thrust is
produced because the shape of the duct allows the duct to carry a
thrust force. In order to maximize efficiency, ducts typically
place the fan in a generally cylindrical section of the duct and
include a generally quarter toroidal inlet upstream of the fan and
a generally frusto-conical diffuser section downstream of the fan.
This arrangement accelerates the air across the inlet and
decelerates the air at the diffuser, thereby creating a pressure
differential on the duct across the fan disk, resulting in
additional thrust. However, the duct must have a sufficient length
to fully decelerate the airflow in order to maximize the additional
thrust. As such, fitting ducts around the forward-facing propellers
of a compound helicopter would create large surfaces that would
suffer ill effects from the downwash of the main rotor while
hovering.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is an oblique view of an aircraft in a forward-flight
mode with thrusters having aligned thrust vectors, according to
this disclosure.
[0004] FIG. 2 is an oblique view of the aircraft of FIG. 1 in a
hover mode with the thrusters having skewed thrust vectors.
[0005] FIG. 3 is an oblique view of a thruster of the aircraft of
FIG. 1
[0006] FIG. 4A is an oblique view of a first portion of a
differential thrust vectoring system, according to this
disclosure.
[0007] FIG. 4B is a top view of the differential thrust vectoring
system of FIG. 4A.
[0008] FIG. 4C is an oblique view of a second portion of the
differential thrust vectoring system of FIG. 4A.
[0009] FIG. 5A is an oblique view of another differential thrust
vectoring system, according to this disclosure.
[0010] FIG. 5B is a top view of the differential thrust vectoring
system of FIG. 5A.
[0011] FIG. 6A is an oblique view of a first portion of another
differential thrust vectoring system, according to this
disclosure.
[0012] FIG. 6B is a top view of the differential thrust vectoring
system of FIG. 6A.
[0013] FIG. 6C is an oblique view of a second portion of the
differential thrust vectoring system of FIG. 6A.
DETAILED DESCRIPTION
[0014] While the making and using of various embodiments of this
disclosure are discussed in detail below, it should be appreciated
that this disclosure provides many applicable inventive concepts,
which can be embodied in a wide variety of specific contexts. The
specific embodiments discussed herein are merely illustrative and
do not limit the scope of this disclosure. In the interest of
clarity, not all features of an actual implementation may be
described in this disclosure. It will of course be appreciated that
in the development of any such actual embodiment, numerous
implementation-specific decisions must be made to achieve the
developer's specific goals, such as compliance with system-related
and business-related constraints, which will vary from one
implementation to another.
[0015] In this disclosure, reference may be made to the spatial
relationships between various components and to the spatial
orientation of various aspects of components as the devices are
depicted in the attached drawings. However, as will be recognized
by those skilled in the art after a complete reading of this
disclosure, the devices, members, apparatuses, etc. described
herein may be positioned in any desired orientation. Thus, the use
of terms such as "above," "below," "upper," "lower," or other like
terms to describe a spatial relationship between various components
or to describe the spatial orientation of aspects of such
components should be understood to describe a relative relationship
between the components or a spatial orientation of aspects of such
components, respectively, as the device described herein may be
oriented in any desired direction. In addition, the use of the term
"coupled" throughout this disclosure may mean directly or
indirectly connected, moreover, "coupled" may also mean permanently
or removably connected, unless otherwise stated.
[0016] This disclosure divulges differential thrust vectoring
systems and an aircraft for use thereon. Each differential thrust
vectoring system disclosed herein is configured to enable rotation
of a pair of thrusters of an aircraft relative to the fuselage by
varying amounts. The differential thrust vectoring systems include
a first thruster rotation assembly with a first spindle coupled for
common rotation with a first thruster and a second thruster
rotation assembly with a second spindle coupled for common rotation
with a second thruster. The differential thrust vectoring systems
enable the thrusters to rotate between a hover position, wherein
the thrust vectors are in a generally vertical orientation
providing lift to the aircraft, and a forward-flight position,
wherein the thrust vectors are in a generally horizontal position
providing forward thrust to the aircraft.
[0017] At least one embodiment includes a main actuator configured
to commonly rotate the first and second spindle and a trim actuator
configured to rotate one of the first and second spindles relative
to the other. When the thrusters are in the hover position, the
differential thrust vectoring system may rotate the thrusters
relative to each other for providing yaw and/or anti-torque
functionality. When the thrusters are in the forward-flight
position, the differential thrust vectoring system may rotate the
thrusters relative to each other for providing roll
functionality.
[0018] At least a second embodiment includes a single actuator and
a planetary gear system coupled between the first and second
spindles. The actuator causes both spindles to rotate, but the
planetary gear system is configured to cause the first and second
spindles to rotate at different rates. In this embodiment, the
thrust vectors are fixed in a generally parallel orientation in the
forward-flight position and the thrust vectors are automatically
skewed to a predetermined deviation angle when rotated to the hover
position.
[0019] FIGS. 1 and 2 show an aircraft 100 that is convertible
between a forward-flight mode, which allows for high-speed
forward-flight as well as horizontal takeoff and landing (shown in
FIG. 1) and a hover mode, which allows for vertical takeoff and
landing, hovering, and low speed directional movement (shown in
FIG. 2). Aircraft 100 includes a fuselage 102 coupled to an
airframe housed therein, a tail section 104 including vertical
stabilizers 106 and horizontal stabilizers 108, a main rotor 110
including a plurality of main rotor blades 112 configured to rotate
about a main mast axis 114, wings 116 extending from either side of
fuselage 102, a first thruster 118 positioned at an outboard end of
one wing 116, and a second thruster 120 positioned at an outboard
end of the other wing 116.
[0020] As best shown in FIG. 3, first thruster 118 comprises a
ducted fan including a rotor assembly 122, a stator assembly 124,
and a duct 126 surrounding rotor assembly 122 and stator assembly
124. Rotor assembly 122 includes a plurality of rotor blades 128
configured to rotate about a mast axis 130. Rotation of rotor
blades 128 about mast axis 130 generates thrust along a first
thrust vector 132 that is coaxial with mast axis 130. The direction
of first thrust vector 132 may be modified by using a differential
thrust vectoring system, as described below, to rotate first
thruster 118 about a tilt axis 134. Stator assembly 124 is
positioned downstream of rotor blades 128 and includes a stator hub
136 centrally located within duct 126 and a plurality of stator
vanes 138 coupled between duct 126 and stator hub 136. Stator hub
136 houses a mechanism therein configured to provide rotational
energy to rotor assembly 122. The mechanism may comprise an
electric motor configured to produce rotational energy.
Alternatively, the mechanism may comprise a gearbox therein
configured to deliver rotational energy to rotor assembly 122,
wherein the gearbox receives rotational energy from a driveshaft
passing through an attachment post 140 and the adjacent stator vane
138. The magnitude of first thrust vector 132 may be modified by
including collective control of the pitch of rotor blades 128
and/or speed control of the mechanism configured to provide
rotational energy. To provide additional thrust control, stator
vanes 138 may be movable. Movement of stator vanes 138 may enable
first thrust vector 132 to deviate from mast axis 130.
[0021] First thruster 118 and second thruster 120 are structurally
similar. As such, second thruster 120 also comprises a ducted fan
including a rotor assembly 142, a stator assembly 144, and a duct
146 surrounding rotor assembly 142 and stator assembly 144. Rotor
assembly 142 includes a plurality of rotor blades 148 configured to
rotate about a mast axis 150. Rotation of rotor blades 148 about
mast axis 150 generates thrust along a second thrust vector 152
that is coaxial with mast axis 150. The direction of second thrust
vector 152 may be modified by using a differential thrust vectoring
system, as described below, to rotate second thruster 120 about
tilt axis 134. Stator assembly 144 is positioned downstream of
rotor blades 148 and includes a stator hub 156 centrally located
within duct 146 and a plurality of stator vanes 158 coupled between
duct 146 and stator hub 156. Stator hub 156 houses a mechanism
therein configured to provide rotational energy to rotor assembly
142. The mechanism may comprise an electric motor configured to
produce rotational energy. Alternatively, the mechanism may
comprise a gearbox therein configured to deliver rotational energy
to rotor assembly 142, wherein the gearbox receives rotational
energy from a driveshaft passing through an attachment post and the
adjacent stator vane 158. The magnitude of second thrust vector 152
may be modified by including collective control of the pitch of
rotor blades 148 and/or speed control of the mechanism configured
to provide rotational energy. To provide additional thrust control,
stator vanes 158 may be movable. Movement of stator vanes 158 may
enable second thrust vector 152 to deviate from mast axis 150.
While first thruster 118 and second thruster 120 are shown as
ducted fans, it should be understood that first thruster 118 and
second thruster 120 could comprise any type of mechanism capable of
producing thrust.
[0022] Referring again to FIG. 1, aircraft 100 is shown in
forward-flight mode, wherein first thrust vector 132 and second
thrust vector 152 are generally horizontal and in a substantially
parallel relationship. It should be understood that first thrust
vector 132 and second thrust vector 152 may deviate from parallel
by a few degrees depending on airflow around fuselage 102. As such,
for this specification and the claims appended hereto, the phrase
"substantially parallel" should include vectors within three
degrees of parallelism. With first thruster 118 and second thruster
120 generating forward thrust, lift is generated by wings 116.
Depending on the forward airspeed and the configuration of wings
116, wings 116 may provide a substantial percentage of the lift
required to maintain altitude. In this scenario, main rotor 110 may
simply be allowed to autorotate and maneuverability of aircraft 100
may be provided by including rudders and/or elevators on the
trailing ends of vertical stabilizers 106 and/or horizontal
stabilizers 108, respectively. As discussed below, the differential
thrust vectoring system may enable relative rotation of first
thrust vector 132 and second thrust vector 152 providing roll
functionality in forward-flight mode. If wings 116 do not provide
sufficient lift, rotational energy is provided to main rotor 110
and lift as well as directional thrust is generated by main rotor
blades 112, which may be collectively or cyclically pitched. When
rotational energy is provided to main rotor 110 in forward-flight
mode, vertical stabilizers 106 may provide sufficient anti-torque
to counter the torque effects of main rotor 110.
[0023] Referring now to FIG. 2, aircraft 100 is shown in hover
mode, wherein first thrust vector 132 and second thrust vector 152
are generally vertical and are skewed. In hover mode, rotational
energy is provided to main rotor 110 and lift as well as
directional thrust is generated by main rotor blades 112, while
first thruster 118 and second thruster 120 generate additional
lift. In addition, the skewed orientation of first thrust vector
132 and second thrust vector 152 provides anti-torque to overcome
the torque effects of main rotor 110. As described below, the
differential thrust vectoring system may enable the angle between
first thrust vector 132 and second thrust vector 152 to vary,
thereby providing yaw control of aircraft 100. Yaw control may also
be provided by adjusting the magnitude of first thrust vector 132
and/or second thrust vector 152, as described above. Alternatively,
or additionally, aircraft 100 may include other conventional
anti-torque/yaw control mechanisms such as a tail rotor or NOTAR
system.
[0024] Referring now to FIGS. 4A-4C, a differential thrust
vectoring system 200 is illustrated with reference to use with
aircraft 100. Differential thrust vectoring system 200 includes a
first thruster rotation assembly 202, a second thruster rotation
assembly 204, an actuator 206, and a planetary gear system 208. As
shown in FIGS. 4A and 4B, first thruster rotation assembly 202
includes a first spindle 210 configured to be coupled to first
thruster 118 for common rotation therewith about tilt axis 134.
First spindle 210 may include a flange for axial bolting to
attachment post 140. Alternatively, or additionally, first spindle
210 may fit inside attachment post 140, or attachment post 140 may
fit inside first spindle 210, to provide for radial bolting. First
spindle 210 is rotatably coupled to a first pillow block assembly
212 which includes a first pedestal 214 and a second pedestal 216
axially spaced from first pedestal 214. First pedestal 214 and
second pedestal 216 are configured to be coupled to the airframe
via plates 218 and 220, respectively. First spindle 210 is
rotatably coupled to first pedestal 214 and second pedestal 216 via
roller bearings 222 and 224, respectively. While first pillow block
assembly 212 is shown with two pedestals, it should be understood
that it may include one or more.
[0025] As shown in FIGS. 4B and 4C, second thruster rotation
assembly 204 includes a second spindle 226 configured to be coupled
to second thruster 120 for common rotation therewith about tilt
axis 134. Second spindle 226 may include a flange for axial bolting
to the attachment post of second thruster 120. Alternatively, or
additionally, second spindle 226 may fit inside the attachment
post, or the attachment post may fit inside second spindle 226, to
provide for radial bolting. Second spindle 226 is rotatably coupled
to a second pillow block assembly 228 which includes a first
pedestal 230 and a second pedestal 232 axially spaced from first
pedestal 230. First pedestal 230 and second pedestal 232 are
configured to be coupled to the airframe via plates 234 and 236,
respectively. Second spindle 226 is rotatably coupled to first
pedestal 230 and second pedestal 232 via roller bearings 238 and
240, respectively. While second pillow block assembly 228 is shown
with two pedestals, it should be understood that it may include one
or more.
[0026] As shown in FIG. 4A, planetary gear system 208 includes a
ring gear 242, a plurality of planetary gears 244, and a sun gear
246. Ring gear 242 is coupled to first spindle 210 for common
rotation therewith about tilt axis 134. Ring gear 242 includes a
pair of tabs 248 configured to rotatably couple ring gear 242 to
actuator 206. As such, actuator 206 is coupled to first spindle 210
through ring gear 242. However, actuator 206 may be directly
coupled to first spindle 210. Sun gear 246 is at the center of
planetary gear system 208 and is fixed in position by a bracket
250. Planetary gears 244 are coupled together via a planetary gear
carrier 252 which includes a post 254 extending therefrom. As shown
in FIG. 4C, planetary gear system 208 further includes a band 256
coupled to second spindle 226. Band 256 includes a projection 258
containing a roller bearing 260 configured to receive post 254
therein. While planetary gear system 208 is shown with a
non-rotatable sun gear 246, it should be understood that that
instead, ring gear 242 may be fixed and planetary gear carrier 252
is coupled to first spindle 210 and actuator 206 while sun gear is
coupled for common rotation with second spindle 226.
[0027] In operation, actuation of actuator 206 causes ring gear
242, first spindle 210, and first thruster 118 to rotate together
about tilt axis 134. Because sun gear 246 is fixed, rotation of
ring gear 242 causes planetary gears 244, along with planetary gear
carrier 252, band 256, second spindle 226, and second thruster 120,
to also rotate about tilt axis 134, but at a slower rate of
rotation. That is, actuation of actuator 206 will cause both first
thruster 118 and second thruster 120 to rotate about tilt axis 134,
but first thruster 118 will rotate further than second thruster
120. This may be particularly useful on a compound helicopter. For
example, in forward-flight mode of aircraft 100, actuator 206 is in
a first position wherein first thrust vector 132 and second thrust
vector 152 are substantially parallel (as shown in FIG. 1), and
anti-torque is provided by vertical stabilizers 106. When it is
desirable to transition to hover mode, actuator 206 is actuated to
a second position, wherein first thrust vector 132 and second
thrust vector 152 are skewed to a predetermined angle (as shown in
FIG. 2). Because first thrust vector 132 has rotated past main mast
axis 114 and second thrust vector 152 has not, the thrust produced
along those vectors provides anti-torque to overcome the torque
effects generated by main rotor 110.
[0028] While differential thrust vectoring system 200 is shown with
actuator 206 as a linear actuator, it should be understood that
actuator 206 may comprise a rotary actuator. Moreover, actuator 206
may be pneumatic, hydraulic, electric, or electromagnetic. In
addition, differential thrust vectoring system 200 may be
configured such that failure of actuator 206 results in first
thruster 118 and second thruster 120 automatically defaulting to
either the hover position or the forward flight position, depending
on the mission of the aircraft 100 and the preference for a
vertical landing versus a horizontal landing. Furthermore,
differential thrust vectoring system 200 may be configured to
permit a variety of types of power transfer therethrough to the
mechanisms configured to deliver rotational energy to rotor
assembly 122 and rotor assembly 142. For example, differential
thrust vectoring system 200 may be configured to position a gearbox
between first thruster rotation assembly 202 and second thruster
rotation assembly 204 wherein a first driveshaft may pass through
an opening in sun gear 246 and extend through first spindle 210 to
provide rotational energy to first rotor assembly 122 and a second
driveshaft may pass through second spindle 226 to provide
rotational energy to second rotor assembly 142. Alternatively,
first spindle 210 and second spindle 226 may be configured to pass
electrical power via cables to electric motors housed within stator
hub 136 and stator hub 156 or pass hydraulic power via tubing to
hydraulic motors housed with stator hub 136 and stator hub 156.
First spindle 210 and second spindle 226 may be configured to pass
the cables or tubing through the entire lengths thereof and/or they
may include openings in the sidewalls configured to pass the cables
or tubing therethrough.
[0029] Referring now to FIGS. 5A and 5B, a differential thrust
vectoring system 300 is illustrated with reference to use with
aircraft 100. Differential thrust vectoring system 300 includes a
first thruster rotation assembly 302, a second thruster rotation
assembly 304, a linear main actuator 306, and a linear trim
actuator assembly 308. First thruster rotation assembly 302
includes a first spindle 310 configured to be coupled to first
thruster 118 for common rotation therewith about tilt axis 134.
First spindle 310 may include a flange for axial bolting to
attachment post 140. Alternatively, or additionally, first spindle
310 may fit inside attachment post 140, or attachment post 140 may
fit inside first spindle 310, to provide for radial bolting. First
spindle 310 is rotatably coupled to a first pillow block assembly
312 which includes a first pedestal 314 and a second pedestal 316
axially spaced from first pedestal 314. First pedestal 314 and
second pedestal 316 are configured to be coupled to the airframe
via plates 318 and 320, respectively. First spindle 310 is
rotatably coupled to first pedestal 314 and second pedestal 316 via
roller bearings 322 and 324, respectively. While first pillow block
assembly 312 is shown with two pedestals, it should be understood
that it may include one or more.
[0030] Second thruster rotation assembly 304 includes a second
spindle 326 configured to be coupled to second thruster 120 for
common rotation therewith about tilt axis 134. Second spindle 326
may include a flange for axial bolting to the attachment post of
second thruster 120. Alternatively, or additionally, second spindle
326 may fit inside the attachment post, or the attachment post may
fit inside second spindle 326, to provide for radial bolting.
Second spindle 326 is rotatably coupled to a second pillow block
assembly 328 which includes a first pedestal 330 and a second
pedestal 332 axially spaced from first pedestal 330. First pedestal
330 and second pedestal 332 are configured to be coupled to the
airframe via plates 334 and 336, respectively. Second spindle 326
is rotatably coupled to first pedestal 330 and second pedestal 332
via roller bearings 338 and 340, respectively. While second pillow
block assembly 328 is shown with two pedestals, it should be
understood that it may include one or more.
[0031] Linear trim actuator assembly 308 includes a ring 342
coupled to first spindle 310, a band 356 coupled to second spindle
326, and a linear trim actuator 344 coupled between ring 342 and
band 356. Ring 342 includes a pair of tabs 348 configured to
rotatably couple ring 342 to linear main actuator 306. As such,
linear main actuator 306 is coupled to first spindle 310 through
ring 342. However, linear main actuator 306 may be directly coupled
to first spindle 310. Ring 342 further includes a projection 346
configured to rotatably couple to linear trim actuator 344. Band
356 includes also includes a projection 350 configured to rotatably
couple to linear trim actuator 344.
[0032] In operation, actuation of linear main actuator 306 causes
ring 342, first spindle 310, and first thruster 118 to rotate
together about tilt axis 134. Because ring 342 is coupled to band
356 via linear trim actuator 344, second spindle 326 and second
thruster 120 also rotate about tilt axis 134 in response to
actuation of linear main actuator 306. Differential rotation of
first thruster 118 and second thruster 120 is provided by linear
trim actuator 344. That is, actuation of linear trim actuator 344
causes band 356, second spindle 326, and second thruster 120 to
rotate relative to ring 342, first spindle 310, and first thruster
118. Accordingly, in forward-flight mode of aircraft 100, both
linear main actuator 306 and linear trim actuator 344 are in first
positions, wherein first thrust vector 132 and second thrust vector
152 are substantially parallel (as shown in FIG. 1), and
anti-torque is provided by vertical stabilizers 106. When it is
desirable to transition to hover mode, both linear main actuator
306 and linear trim actuator 344 are actuated to second positions,
and first thrust vector 132 and second thrust vector 152 are skewed
to a predetermined angle (as shown in FIG. 2). Because first thrust
vector 132 has rotated past main mast axis 114 and second thrust
vector 152 has not, the thrust produced along those vectors
provides anti-torque to overcome the torque effects generated by
main rotor 110. Further actuation of linear main actuator 306 and
linear trim actuator 344 can further vary the angle between first
thrust vector 132 and second thrust vector 152, thereby varying the
rotational force on aircraft 100 and providing yaw control. The
same principal can be applied during forward-flight mode. That is,
deviation of first thrust vector 132 and second thrust vector 152
from the substantially parallel orientation during forward flight
can provide roll capabilities.
[0033] Linear main actuator 306 and linear trim actuator 344 may be
pneumatic, hydraulic, electric, or electromagnetic. In addition,
differential thrust vectoring system 300 may be configured such
that failure of linear main actuator 306 and/or linear trim
actuator 344 results in first thruster 118 and second thruster 120
automatically defaulting to either the hover position or the
forward-flight position, depending on the mission of the aircraft
100 and the preference for a vertical landing versus a horizontal
landing. Furthermore, differential thrust vectoring system 300 may
be configured to permit a variety of types of power transfer
therethrough to the mechanisms configured to deliver rotational
energy to rotor assembly 122 and rotor assembly 142. For example,
differential thrust vectoring system 300 may be configured to
position a gearbox between first thruster rotation assembly 302 and
second thruster rotation assembly 304 wherein a first driveshaft
may pass through first spindle 310 to provide rotational energy to
first rotor assembly 122 and a second driveshaft may pass through
second spindle 326 to provide rotational energy to second rotor
assembly 142. Alternatively, first spindle 310 and second spindle
326 may be configured to pass electrical power via cables to
electric motors housed within stator hub 136 and stator hub 156 or
pass hydraulic power via tubing to hydraulic motors housed with
stator hub 136 and stator hub 156. First spindle 310 and second
spindle 326 may be configured to pass the cables or tubing through
the entire lengths thereof and/or they may include openings in the
sidewalls configured to pass the cables or tubing therethrough.
[0034] Referring now to FIGS. 6A-6C, a differential thrust
vectoring system 400 is illustrated with reference to use with
aircraft 100. Differential thrust vectoring system 400 includes a
first thruster rotation assembly 402, a second thruster rotation
assembly 404, a rotary main actuator 406, and a rotary trim
actuator assembly 408. As shown in FIGS. 6A and 6B, first thruster
rotation assembly 402 includes a first spindle 410 configured to be
coupled to first thruster 118 for common rotation therewith about
tilt axis 134. First spindle 410 may include a flange for axial
bolting to attachment post 140. Alternatively, or additionally,
first spindle 410 may fit inside attachment post 140, or attachment
post 140 may fit inside first spindle 410, to provide for radial
bolting. First spindle 410 is rotatably coupled to a first pillow
block assembly 412 which includes a first pedestal 414 and a second
pedestal 416 axially spaced from first pedestal 414. First pedestal
414 and second pedestal 416 are configured to be coupled to the
airframe via plates 418 and 420, respectively. First spindle 410 is
rotatably coupled to first pedestal 414 and second pedestal 416 via
roller bearings 422 and 424, respectively. While first pillow block
assembly 412 is shown with two pedestals, it should be understood
that it may include one or more.
[0035] As shown in FIGS. 6B and 6C, second thruster rotation
assembly 404 includes a second spindle 426 configured to be coupled
to second thruster 120 for common rotation therewith about tilt
axis 134. Second spindle 426 may include a flange for axial bolting
to the attachment post of second thruster 120. Alternatively, or
additionally, second spindle 426 may fit inside the attachment
post, or the attachment post may fit inside second spindle 426, to
provide for radial bolting. Second spindle 426 is rotatably coupled
to a second pillow block assembly 428 which includes a first
pedestal 430 and a second pedestal 432 axially spaced from first
pedestal 430. First pedestal 430 and second pedestal 432 are
configured to be coupled to the airframe via plates 434 and 436,
respectively. Second spindle 426 is rotatably coupled to first
pedestal 430 and second pedestal 432 via roller bearings 438 and
440, respectively. While second pillow block assembly 428 is shown
with two pedestals, it should be understood that it may include one
or more.
[0036] Rotary trim actuator assembly 408 includes a first ring gear
442 coupled to first spindle 410, a second ring gear 456 coupled to
second spindle 426, and a rotary trim actuator 444 coupled between
first ring gear 442 and second ring gear 456. First ring gear 442
includes external teeth 448 configured to mesh with external teeth
446 of rotary main actuator 406. As such, rotary main actuator 406
is coupled to first spindle 410 through first ring gear 442. First
ring gear 442 further includes a bracket 450 configured to couple
rotary trim actuator 444 thereto. Second ring gear 456 includes
internal teeth 452 configured to mesh with external teeth 454 of
rotary trim actuator 444.
[0037] In operation, actuation of rotary main actuator 406 causes
first ring gear 442, first spindle 410, and first thruster 118 to
rotate together about tilt axis 134. Because first ring gear 442 is
coupled to second ring gear 456 via rotary trim actuator 444,
second spindle 426 and second thruster 120 also rotate about tilt
axis 134 in response to actuation of rotary main actuator 406.
Differential rotation of first thruster 118 and second thruster 120
is provided by rotary trim actuator 444. That is, actuation of
rotary trim actuator 444 causes second ring gear 456, second
spindle 426, and second thruster 120 to rotate relative to first
ring gear 442, first spindle 410, and first thruster 118.
Accordingly, in forward-flight mode of aircraft 100, both rotary
main actuator 406 and rotary trim actuator 444 are in first
positions, wherein first thrust vector 132 and second thrust vector
152 are substantially parallel (as shown in FIG. 1), and
anti-torque is provided by vertical stabilizers 106. When it is
desirable to transition to hover mode, both rotary main actuator
406 and rotary trim actuator 444 are actuated to second positions,
and first thrust vector 132 and second thrust vector 152 are skewed
to a predetermined angle (as shown in FIG. 2). Because first thrust
vector 132 has rotated past main mast axis 114 and second thrust
vector 152 has not, the thrust produced along those vectors
provides anti-torque to overcome the torque effects generated by
main rotor 110. Further actuation of rotary main actuator 406 and
rotary trim actuator 444 can further vary the angle between first
thrust vector 132 and second thrust vector 152, thereby varying the
rotational force on aircraft 100 and providing yaw control. The
same principal can be applied during forward-flight mode. That is,
deviation of first thrust vector 132 and second thrust vector 152
from the substantially parallel orientation during forward flight
can provide roll capabilities.
[0038] Rotary main actuator 406 and rotary trim actuator 444 may be
pneumatic, hydraulic, electric, or electromagnetic. In addition,
differential thrust vectoring system 400 may be configured such
that failure of rotary main actuator 406 and/or rotary trim
actuator 444 results in first thruster 118 and second thruster 120
automatically defaulting to either the hover position or the
forward-flight position, depending on the mission of the aircraft
100 and the preference for a vertical landing versus a horizontal
landing. Furthermore, differential thrust vectoring system 400 may
be configured to permit a variety of types of power transfer
therethrough to the mechanisms configured to deliver rotational
energy to rotor assembly 122 and rotor assembly 142. For example,
differential thrust vectoring system 400 may be configured to
position a gearbox between first thruster rotation assembly 402 and
second thruster rotation assembly 404 wherein a first driveshaft
may pass through first spindle 410 to provide rotational energy to
first rotor assembly 122 and a second driveshaft may pass through
second spindle 426 to provide rotational energy to second rotor
assembly 142. Alternatively, first spindle 410 and second spindle
426 may be configured to pass electrical power via cables to
electric motors housed within stator hub 136 and stator hub 156 or
pass hydraulic power via tubing to hydraulic motors housed with
stator hub 136 and stator hub 156. First spindle 410 and second
spindle 426 may be configured to pass the cables or tubing through
the entire lengths thereof and/or they may include openings in the
sidewalls configured to pass the cables or tubing therethrough.
[0039] While differential thrust vectoring systems 200, 300, and
400 are referenced for use with aircraft 100, a compound
helicopter, it should be understood that they may be utilized on
any aircraft that may benefit from altering the thrust vectors of a
pair of thrusters.
[0040] At least one embodiment is disclosed, and variations,
combinations, and/or modifications of the embodiment(s) and/or
features of the embodiment(s) made by a person having ordinary
skill in the art are within the scope of the disclosure.
Alternative embodiments that result from combining, integrating,
and/or omitting features of the embodiment(s) are also within the
scope of the disclosure. Where numerical ranges or limitations are
expressly stated, such express ranges or limitations should be
understood to include iterative ranges or limitations of like
magnitude falling within the expressly stated ranges or limitations
(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater
than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a
numerical range with a lower limit, R.sub.l, and an upper limit,
R.sub.u, is disclosed, any number falling within the range is
specifically disclosed. In particular, the following numbers within
the range are specifically disclosed:
R=R.sub.l+k*(R.sub.u-R.sub.l), wherein k is a variable ranging from
1 percent to 100 percent with a 1 percent increment, i.e., k is 1
percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50
percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 95
percent, 98 percent, 99 percent, or 100 percent. Moreover, any
numerical range defined by two R numbers as defined in the above is
also specifically disclosed. Use of the term "optionally" with
respect to any element of a claim means that the element is
required, or alternatively, the element is not required, both
alternatives being within the scope of the claim. Use of broader
terms such as comprises, includes, and having should be understood
to provide support for narrower terms such as consisting of,
consisting essentially of, and comprised substantially of.
Accordingly, the scope of protection is not limited by the
description set out above but is defined by the claims that follow,
that scope including all equivalents of the subject matter of the
claims. Each and every claim is incorporated as further disclosure
into the specification and the claims are embodiment(s) of the
present invention. Also, the phrases "at least one of A, B, and C"
and "A and/or B and/or C" should each be interpreted to include
only A, only B, only C, or any combination of A, B, and C.
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